Equalizing mechanism for reciprocating machines.



No. 741,470. PATENTED OCT. 13, 1903. A. G. EASTWOOD.

EQUALIZINGMEGHANISM FOR RECIPROGATING MACHINES. APPLICATION FILED NOV. 29. 1902.

no 110mm. 2 sgnnTs-snnm 1.

PATENTED OCT. 1a, 1903. A. c. EASTWO0D.- EQUALIZING MECHANISM FOR REGIPROGATING MACHINES.

2 SHEETS-SHEET 2.

APPLICATION FILED K012911902.

NO MODEL.

QWFFEW Y I N m! NORRIS PETERS co. PHOTOJJTNQ. wAsmNoTm, a. r

- UNITED STATES Patented October 13, 1903.

, PATENT OFFICE.

. ARTHUR C. EASTWOOD, OF CLEVELAND, OHIO.

EQUALIZING MECHANISM FOR RECIPROC-ATING MACHINES.

SPECIFICATION forming part of Letters Patent No. 741,470, dated October 13,1903- 7 Application filed November 29. 1902. Serial No.'133,190. (N0 model.)

To all whom it may concern:

Be it known that I, ARTHUR 0. EAST WOOD,

a citizen of the United States, and a resident;

of Cleveland, Ohio, have invented certain Improvements in Equalizing Mechanism for Beciprocating Machines, of which the following is a specification.

My invention relates to certain improvements in mechanism for equalizing the power required fol-the operation of machines having reciprocating parts, and more particularly consists in an improved device for equalizing throughout each complete cycle of operations the power necessary for the operation of that class of machine tools commonly known as planers. In tools of this class the work to be operated upon 'is generally clamped to a table or platen which is given a reciprocating motion relatively to one or more cutting-tools, and for. machining heavy pieces the table must of necessity be of great weight to properly support the weight of the object operated upon without distortion, it being evident that when a reciprocating motion is imparted to the table the motion of the combined mass of said table and its load must be reversed in direction at both ends of the stroke. I have found by practical experiment that it requires from four to twelve times more power to produce this reversal of motion than is required to drive the table,with itsload, at a uniform speed under cut. Hence with a tool of this classasat present designed it is necessary to provide power four to twelve times in excess of that necessary to operate the tool. When cutting, such excess of power is required, first, to overcome the momentum due to the forward motion of the table and its load, and, second, to accelerate the motion of these bodies in the reverse direction, the relative amount ofsuch excess of power required depending upon the mass of the table and its load, as well a'sthe length of time in which the reversal of itsmovement is required to be made.

In tools of the class above referred to as at present constructed all of the energy stored up in the mass of the table and the objects carried thereby due tofltheir momentum is wasted at each reversal of its movement, and it is the overcoming of this force which results in the slipping and burning of belts and the heating of clutches invariably found in the operation of all large planers. The object of my invention is to store up at the end of each strokethe energy due to the momentum of the table and its load and to return this energy to the same at the beginning of the return stroke, so that it may be utilized in accelerating the table and its load, thus equalizing or rendering more uniform the power required to operate the tool. A further object of the invention is to materially reduce the power which ordinarily has to be available to operate the tool and to pre-' vent the excessive strain ordinarily brought upon the driving mechanism in order to reverse the movement of the planer-table.

" The above objects I attain as hereinafter set forth, reference being had to the accompanying drawings, in which- Figure 1 is a side elevation of a planer, showing my improved power-equalizing device attached thereto. Fig. 2 is a plan view of the machine shown in Fig. 1, further illustrating myinvention. Fig. 3 is a'view, partly in diagram, showing the electrical connec: tions and detail construction of the preferred form of my device. Figs. 4 and 5 are diagrammatic views showing special forms of my invention. I

In the'above drawings, A represents the bed of aplaner of any of the well-known forms, having an upwardly-projecting pair of standards or cheek-pieces 13, upon which, is movably supported the tool-carriage C, having a tool 0.

D is'a reciprocating table shown as carrying a body (1 to be operated upon by the tool. The under part of the table is provided with a rack, (indicated in dotted lines on Fig. 2 at d,) and there is a shaft (:1 carrying a pinion (indicated at (1 in mesh with said rack. A gear-wheel d meshes with a pinion a on an auxiliary driving-shaft a, this latter being connected to a main driving-shaft a through the bevel-gears a Two pairs of fast-and loose pulleys a and a are shown as connected to the shaft o by which the planer-table is reciprocated in the well-known manner.

As shown in Fig. 3, the shaft (1 is provided with a headed projecting pin 01 which car- 'ries an iron disk E parallel to the face of the gear-wheel d This disk forms a portion of ICO any desired form of magnetic clutch, the windings of which are shown at e. A crankpin 6 extends from the outer face of the disk E, and a rod 0 operatively connects said crank-pin with a piston f, belonging to a cylinder F, preferably carried, as shown, by the framework of the planer. In the device illustrated the end of the cylinder nearest the clutch E is open, while the other end is provided with an adjustable head f, this latter having a threaded bolt f fixed in it, which is provided with a nut f, by which said head may be adjusted in the cylinder. Supporting-screws f 4 are also provided, and these extend through what would ordinarily be the rear head of the cylinder and engage the adjustable head f, so as to retain it in any given position without undue strain on the bolt f Lugs or dogs a and a are adjustably fixed to the side of the table, and there is an electric switch H, supported by the planer-bed, having three segmental contactpieces h, 7t, and 7712. These are preferably constructed on the arcs of concentric circles, the two pieces h and 71 being formed on equal radii. The switch-arm 71 is pivoted at 71,4 and carries a piece 7L5, designed to electrically connect either of the segments h or kg with the segment h. The switch-arm h has an extended portion, upon which is secured a weight 72-", whose function is to maintain said arm in a substantially vertical position or return it to such position afterithas been moved from the same. The segments h and 72, are electrically connected to each other and to one end of the windings of the magnetic clutch E, the other end of said winding being connected to one terminal of an electrical generator 7L7, while thesecond terminalofthisgeneratorisin connection with the segment 7?. of the switch. As long as the lever or switch arm 7L3 is in its vertical position the circuit through the magnetic clutch is open and the wheel d is free to revolveindependentlythereof. When, however, said lever isinolined sufliciently to permit the piece 71, to contact with either of the segments h or 71 and the segment h, current is permitted to flow from the generator and causes the clutch to grip and move with the said gear-wheel d. This switching mechanism is so located with respect to the driving and reversing mechanism that at the instant the driving power is removedthat is, in the case illustrated when one of the driving-belts (not shown) is shifted from the tight to the loose pulley a or a -the switch-arm 77, is thrown over and the magnetic clutch energized. Such energization causes the clutch to grip the gear (1 and the piston f is thereby driven forward or into the cylinder F and caused to compress air in the same, thus absorbing and storing up the energy due to the momentum of the table D, with its load d. The reverse driving-belt is in the meantime thrown into action to move the planer-table in the opposite direction, and it will be seen that the compressed air in the cylinder then acts to return energy to the table by assisting in accelerating the motion of the table, it being understood that the switch-arm 72, is held by the dog a, so that the clutch E will continue to engage the face of the gear-wheel 61 It will be evident that the driving-belt or reversing-clutch is thus relieved of a very material portion of the strain to which it would otherwise be subjected during the acceleration of the table as it starts on its return stroke and that in myinvention less external motive power is required for a given acceleration of the table, or if the drivingpower remains the same the table may be more rapidly accelerated than would otherwise be possible. By the time that the piston fhas returned to the end of the cylinder F nearest the clutch the switch-arm 72 has been disengaged from the dog a, so that it is free to return to its normal vertical position, and thereby break the circuit through the magnetic clutch. The wheel 61 is then permitted to revolve independently of the said clutch, and the piston remains in the position shown in Fig. 3 until the dog it engages the switcharm, and the above-noted series of operations is repeated.

It is evident that with a relatively heavy load on the table D the pistonf may be made to travel farther in the cylinder, and thereby more highly compress the air in order to store up and return the increased amount of energy necessarilydealt with. This end may be attained by suitable adjustment of the dogs a and a In order to provide means whereby the motion of the table may be reversed in the same distance of travel irrespective of the load thereupon, I employ the adjustable head f in the cylinder F, by means of which I may adjust the clearance at the inward end of the stroke of the piston f, and thereby the pressure to which the air will be compressed.

While I have illustrated and described my invention as employing a cylinder and piston to store up and deliver the energy of the moving planer-table, it is evident that other mechanical devices may be employed forthis purpose-such, for example, as those shown in Figs. 4 and 5. In the first of these any desired form of clutch (indicated at (1 may be automatically connected to the gear-wheel, as indicated above, there being connected to said clutch a winding-drum 01 having a cable 61 connected to a plate j, in engagement with a spring j, the whole being inclosed in a suitable casing J. In the case of the second construction a weight 7' may be attached to a cable 01 in either case the device serving to store up energy either by compressing the spring or by raising the weight at the end of the movement of the planertable after the driving power has been thrown 0d and being free to act on said clutch to assist in driving the table in the opposite di rection.

It will be evident to those skilled in the art that a mechanical clutch may be employed in place of the magnetic clutch E, as shown in the drawings, such clutch being operated by adjustable dogs fixed to the work-table,

I claim as my invention 1. The combination of a machine having a reciprocating member and means for operating the same, said means including a rotatable portion, a second rotatable member, a device for absorbing and storing energyconnected to said second rotatable member, and

a device operated by the reciprocating member for automatically connecting said two rotatable members, substantially as. described.

2. The combination of a machine having a reciprocable member and means for operating the same, said operating means'including a rotatable disk,a second rotatable disk supported adjacent to the first and provided with an electromagnetic clutching device, an energy-storing device attached to said second disk, an electric switch placed to be operated by the reciprocable portion of the machine, a source of electric current connected to the switch and to the electromagnetic clutching device whereby the two disks may be caused to be clutched together at certain points of the stroke of the reciprocating member, substantially as described.

3. The combination of a machine having a reciprocable member, a rack on said member, means including a toothed wheel operative upon said rack for actuating said reciprocating member, an electromagnetic clutch directly operative upon said toothed wheel, an energy absorbing and storing device connected to said electromagnetic clutch, and means for throwing the clutch into and outof operation, said means being operated automatically by the reciprocating member, substantially as described.

4. The combination of a machine having a reciprocable member provided with a rack, means for operating said reciprocating member, including a toothed wheel and a supporting-shaft therefor, a disk having anelectromagnetic winding upon it and supported upon said shaft, a pin on said disk eccentric to the shaft, a cylinder, a piston in the cylinder, and a connecting-rod between said piston and the pin on the disk,with a switch, a sourceof electric current, and connections -for said elecreciprocating member and means for operating the same, said means includinga rotatable portion, a second rotatable member, a device for absorbing and storing energy connected to said second rotatable member, and a device operated by the reciprocating member for automatically'connecting said two rotatable members, said device including an electromagnetic clutch, a source of current and an electric switch, substantially as described.

6. The combination of a machine having a reciprocating member and means for operating the same, said means including a rotatable portion, a second rotatable member, a device for absorbing and storing energy connected to said second rotatable member, and a device operated by the reciprocating member for automatically connecting said two rotatable members, said device including an electromagnetic clutch, a source of current and an electric switch, with adjustable means for actuating said switch, substantially as described.

7. The combination of a-machine having a reciprocating member and means for operating the same, said means including a rotatable portion, a second rotatable member, a device .for. absorbing and storing energy connected to said second rotatable member, and a-device operated by the reciprocating member for automatically connecting said two rotatable members, said device including an electromagnetic clutch, a sourceof current and an electric switch, with means on the moving part of the machine for actuating the switch, said switch having a movable plate and a con-v tact or contacts on each side of the same,wi th means for normally retaining the plate out of engagement with said contacts, substantially as described.

Intestimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR O. EASTWOOD.

Witnesses: C. W. CoMsTooK,

J ESSEE E. WELLMAN. 

